Flexible abrasive grinders for side sharpenable cutters

ABSTRACT

An abrasive surface provided on a resilient substrate mounted in the path of a side sharpenable cutter. Upon engagement of the side sharpenable cutter with the abrasive surface, the substrate flexes to permit the cutter to slide over the abrasive surface. The substrate is biased toward the cutter sufficiently to achieve grinding of the metal edge of the cutter.

United States Patent 1 1 1111 3,755,997

Edgerton Sept. 4, 1973 [54] FLEXIBLE ABRASIVE GRINDERS FOR SIDE 3,561,202 2/l97l Tupper 56/291 SHARPENABLE CUTTERS FOREIGN PATENTS OR APPLICATIONS [751 Invent: mm Edgemn Canby, 57l,803 9/1945 Great Britain 56/244 [73] Assignee: Omark Industries, Inc., Portland,

g- Primary Examiner-Russell R. Kinsey [22] Filed, Oct 20 1972 Attorney-Robert L. Harrington 211 Appl.No.: 299,441

[57] ABSTRACT 52 vs. 01. 56/244, 56/291 abrasive Surface Provided a resilient Substrate 51 Int. Cl A01d 55/24 mounted in the P Side shatPenable clmer- P [58] Field of Search 56/290, 291, 292, engagement the Side sharpenable cutter with 56/244 245 abrasive surface, the substrate flexes to permit the cutter to slide over the abrasive surface. The substrate is [56] References Cited biased toward the cutter sufficiently to achieve gn'nd- UNITED STATES PATENTS ing of the metal edge of the cutter.

3,545,188 12/1970 Locati 56/245 2 Claims, 3 Drawing Figures FLEXIBLE ABRASIVE GRINDERS FOR SIDE SHARPENABLE CUTTERS This invention relates to impact mowing apparatus and more particularly, to such apparatus having a cutter belt with side sharpenable cutters whereby sharpening of the cutters is achieved while the cutter belt is in motion.

Impact mowing apparatus utilizing flexible cutter belts with side sharpenable cutters are not new as evidenced by US. Pat. No. 3,545,188 issued Dec. 8, 1970 and US. Pat. No. 3,561,202 issued Feb. 9, 1971 and US. Pat. No. 3,660,971 issued May 9, 1972. As will be noted by reference to the above cited patents, an abrasive grinding member is mounted for adjustable movement into the path of the cutters so that as the side sharpenable cutters contact the abrasive surface, the leading edge is sharpened. However, it has been found that where the path of the cutters are not in exact alignment, the contact with the abrasive surface varies and some cutters are ground more than others. Thus, some of the cutters are ground to an excess which accelerates wearing while other cutters are not ground enough to become sharpened.

BRIEF DESCRIPTION The present invention obviates the above problem by providing a spring'biased or resilient mounting finger for the abrasive grinding surface such that the grinding surface is biased into the path of the cutters. As the leading edge of the cutter engages the grinding surface it is bent out of the way while maintaining abrasive contact with the leading edge. Whereas the above description very briefly describes the concept of the present invention, it will be more clearly understood by reference to the following detailed description and drawings wherein:

FIG. 1 is a partial top view of a bar for mounting a cutter belt including a sharpener in accordance with the present invention;

FIG. 2 is a side view of the cuttting belt and sharpener illustrated in FIG. 1; and

FIG. 3 is a perspective view of the cutting belt and sharpener of FIG. 2.

Referring to FIG. 1 of the drawings, the contemplated mower apparatus has a guide bar 10 including a drive sheave 12 and a series of guide sheaves 14 (only one of which is shown). A cutter belt 16 comprised a V-belt 18 having fastened thereto side sharpenable cutters 20. Mounted adjacent to the drive pulley is the sharpening apparatus 22 which will now be described in more detail.

Referring to FIGS. 2 and 3, the cutter belt 16 is designed to be driven from left to right as illustrated. The sharpening apparatus 22 is mounted below the cutter belt 16 by a mounting bracket 24 to a side plate 26 of the guide bar 10. As will be noted, the bracket includes mounting slots 28 through which bolts 30 are inserted thus enabling the bracket to be adjusted within the limits of the slots 28. The bracket 24 carries a mounting shoe 32 from which a flexible resilient steel finger 34 is extended in the direction of the belt movement. As noted in FIGS. 2 and 3, the cutters 20 are fastened to the belt so that the blades 36 extend to the side of the belt (forwardly with respect to the guide bar 10). As particularly seen from FIG. 2, the plane defined by the cutter blade 36 is angled upwardly from the axis defined by the belt (e.g., approximately The leading edge or cutting edge 38 of the blade 36 is substantially parallel to the guide bar (i.e., in a horizontal plane and rearwardly angled with respect to the belt movement.

The flexible finger 34 flexes about the mounting shoe 32 on an axis that is perpendicular to the belt movement and in a plane parallel to but below the plane de fined by the cutting edge as it is carried along a path by the belt 18. The finger is extended upwardly from its axis and urged by the resiliency of the finger into the path of the cutters (during the sharpening operation) to be engaged by the cutting edge 38 as shown in FIG. 2. The continued movement of the belt forces pivotal flexing of the finger 34 as shown by the ghost lines in FIG. 2. A suitable abrasive covering 40 is affixed to the top of the finger 34 to abrade the portion of the blade below and rearwardly of the cutting edge 38. In

operation, when it is desired to sharpen the blades 36, the sharpener 22 is mounted on the guide bar and adjusted to establish the desired angle of the finger with respect to the plane of movement of the cutting edge. It will be understood that this plane of movement for successive cutter blades may vary up and down slightly with the only effect being that it will engage the abrasive covering 40 slightly lower or higher with slightly more or less abrasive action. The difference, however, it so slight as to render the effective results negligible.

Those skilled in the art will become aware of numerous modifications and variations of the invention which is defined not by the specific example set forth above but by the claims appended hereto.

What I claim is:

l. A mower apparatus having a guide bar and an endless cutter belt with side sharpenable cutters affixed thereto mounted for driven rotation on said guide bar, said cutters having cutting blades with leading cutting edges defining a plane as the cutter belt is driven on said guide bar, said cutting blades being angled away from said plane; and the improvement which comprises a sharpener, said sharpener including a bracket affixed to the guide bar, a resilient finger mounted at one end to said bracket and from a position on the side of said plane defined by the cutting edge opposite to the side of the cutting blade, and said finger being extended toward said plane and intersecting said plane at positions between said cutting blade and said resilient finger having an abrasive covering on the side thereof which is engaged by the cutting edge with said cutting edge drawn over the abrasive covering as the finger is forced to flex out of the way of the blade.

2. A mower apparatus as defined in claim 1 wherein the bracket is removably attached to the cutter bar, and including means for adjusting the angle at which the flexible finger intersects the plane defined by said cutting edge. 

1. A mower apparatus having a guide bar and an endless cutter belt with side sharpenable cutters affixed thereto mounted for driven rotation on said guide bar, said cutters having cutting blades with leading cutting edges defining a plane as the cutter belt is driven on said guide bar, said cutting blades being angled away from said plane; and the improvement which comprises a sharpener, said sharpener including a bracket affixed to the guide bar, a resilient finger mounted at one end to said bracket and from a position on the side of said plane defined by the cutting edge opposite to the side of the cutting blade, and said finger being extended toward said plane and intersecting said plane at positions between said cutting blade and said resilient finger having an abrasive covering on the side thereof which is engaged by the cutting edge with said cutting edge drawn over the abrasive covering as the finger is forced to flex out of the way of the blade.
 2. A mower apparatus as defined in claim 1 wherein the bracket is removably attached to the cutter bar, and including means for adjusting the angle at which the flexible finger intersects the plane defined by said cutting edge. 